ohka

桜花

Yokosuka MXY7 "Ohka" Flying Bomb

In the closing months of 1944, the Japanese Navy decided to follow up on the perceived success of the "kamikaze" program by creating a new type of aircraft specifically designed with suicide missions in mind. The Navy also hoped to increase the success rate, while reducing pilot training time to an even lower minimum at a time when boys as young as 16 were being recruited as kamikaze pilots. The result was the Yokosuka corporation's MXY-7 "Ohka" ("cherry blossom").

Nicknamed "Baka" by the Allies (using the Japanese word for "stupid"), the Ohka is technically termed a "rocket-propelled glider" but in reality was less of an aircraft than a crude piloted bomb. The craft had no landing gear and only the most rudimentary steering capability. Incapable of takeoff or landing, the Ohka was released like a bomb from its sling under a specially modified Mitsubishi G4M2e "Betty" bomber. The "pilot," who was drawn from the specially created Jinrai Butai ("Divine Thunder Corps") that exclusively operated the Ohka, sat in a cramped compartment on top of a massive 1200 kilogram warhead and several hundred liters of rocket fuel. The Ohka were painted bright white with a large pink cherry blossom on the nose, symbolizing the pilot's desire to die a beautiful death while falling from the sky like a cherry blossom from a cherry tree.

While en route to the target, the Ohka pilot would sit with the bomber crew, reviewing his mission plan and mentally preparing himself for death. As the appointed target drew within range, he would lower himself into the Ohka and wait for the Morse code signal "dot-dot-dot-dash-dot," upon which the craft would be released. The pilot would then lower the nose of the craft to an appropriate angle and the craft would then accelerate to a maximum gliding speed of 260 knots while descending to an altitude of 1000 meters. To extend the flight time and increase speed, the pilot would then fire three rocket engines in the Ohka's tail, which had a firing endurance of 9 seconds. Aiming for the waterline, he would dive into the enemy ship and perish in the resulting explosion. The 1,200 kilogram warhead was equipped with a delayed-action fuse that would detonate only after the craft had penetrated deep into the bowels of the ship, for maximum damage.

At least that's how it was supposed to work.

In reality the lumbering Betty bombers were too slow and were easily intercepted, often before they got anywhere near close enough to launch the Ohka, which had an effective range of less than 40 kilometers. Out of 75 Ohka missions, only 5 confirmed hits were recorded, with one US destroyer sunk and two other vessels damaged beyond repair. Worse, of the 75 Betty bombers involved, each with a crew of seven trained aviators, at least 60 were shot down with all crew lost.

To overcome this weakness in the delivery system, at least two other models of Ohka were designed, using jet engines to increase range dramatically over the first two models (known as Type-11 and Type-21). The Type-23 Ohka was to have used a thermojet engine to extend the launch range to a distant 126 kilometers, while the gargantuan Type-43 Ohka was to have employed a turbojet engine to achieve a massive range of 270 kilometers. The Type-23 engine was successfully tested, and fuselages were built in quantity to accept it, while the Type-43 concept did not get much farther than the drawing board before the war ended. Neither jet version was ever deployed operationally.

The discovery by the Allied Occupation of hundreds of Ohka aircraft under construction after the war is a testament to Japanese intentions to escalate the use of these flying bombs had the war continued.